He doesn't need to share the VI -- the VI that you copied from the LabVIEW Examples is working perfectly, you just don't understand enough LabVIEW to make it work properly (and maybe don't understand your data well enough to know what to expect).
Here is an updated Front Panel display of the Spectrum VI that you most recently supplied. I made only two changes:
- I added a Waveform Graph that shows the actual Signal data. Note that the Time scale is probably wrong as you specify Frequency in MHz but appear to ignore the label and use 5000 (which LabVIEW treats as 5 kHz) as the frequency: 20474 samples/5 kHz = 4.096 s.
- I allowed the Y Scale on the STFT to Autoscale, which (in turn) allows the Time-Spectrum to be visible.
Your signal appears to be broad-band noise, with possibly a frequency "comb" at intervals of 250 Hz. Don't know what this means, and, I suspect, neither do you.
Did you understand the function of the While Loop in the example? What purpose does it serve in the code as you copied it? What might be a better design to accomplish the same thing without doing the same computation over and over again, 10 times a second? If the answer isn't obvious to you, spend more time with the LabVIEW Tutorials and try to learn LabVIEW. [If you get stuck or need help, we're happy to help ...].
Bob Schor
Search LabVIEW like a graph! 